A power steering mechanism comprises an electric assisting steering motor and a worm screw mounted on an output shaft of said motor and meshing with a toothed wheel for example fastened to the shaft of the steering column or connected to the steering rack via an intermediate pinion.
Generally, the power steering mechanism also comprises a system for automatically compensating the wear of the thread or threads of the worm screw and/or of the teeth of the associated toothed wheel that can occur over time. For more details, reference can, for example, be made to the document DE-A1-100 53 183 illustrating such a wear compensation system.
In this document, the wear compensation system is mounted at one end of the worm screw, the other end of the screw being mounted to rotate inside a housing via a rolling bearing. Between the bearing and the housing, there is arranged a metal tolerance ring allowing a radial displacement of said bearing and of the worm screw towards the toothed wheel in a wear compensation action.
This solution presents the drawback of not making it possible to absorb an angular alignment defect of the axis of the worm screw and of the axis of the housing, in particular in a wear compensation action. Moreover, it is necessary to provide for two distinct elements to be mounted, namely the metal tolerance ring and the rolling bearing.
The present invention aims to remedy these drawbacks.